The structure of the antigenic O-polysaccharide isolated from the lipopolysaccharide produced by enterohemorrhagic Escherichia coli O103:H2 was determined and shown to be composed of d-glucose (1 part), 2-acetamido-2-deoxy-d-glucose (2 parts), 2-acetamido-2-deoxy-d-galactose (1 part), and 3-deoxy-3-(R)-3-hydroxybutyramido-d-fucose (1 part). From the results of methylation analysis, Smith-type periodate oxidation degradation studies, and the use of one- and two-dimensional (1)H and (13)C NMR spectroscopy, the O-polysaccharide antigen was found to be an unbranched polymer of a repeating pentasaccharide unit having the following structure: →2)-β-D-Glcp-(1→2)-β-D-Fucp3NBu-(1→6)-α-D-GlcpNAc-(1→4)-α-D-GalpNAc-(1→3)-β-D-GlcpNAc-(1→, where Bu is (R)-3-hydroxybutyramido.

lipopolysaccharides, structure, O-antigenic polysaccharide, NMR spectroscopy, enteropathogenic, Escherichia coli O103:H2

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
2,3,2	Ac
2,3	aDGalpN	98.7	51.1	69.0	69.8	72.4	61.9
2,2	Ac
2	bDGlcpN	102.1	55.9	79.5	72.5	77.1	62.1
	x?Gro-al	104.1	80.4	61.5


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
2,3,2	Ac
2,3	aDGalpN	5.43	4.19	3.81	4.00	3.87	3.91
2,2	Ac
2	bDGlcpN	4.76	3.79	3.74	3.67	3.44	3.75
	x?Gro-al	5.13	3.96	3.7-3.8


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
2,3,2	Ac
2,3	aDGalpN	98.7/5.43	51.1/4.19	69.0/3.81	69.8/4.00	72.4/3.87	61.9/3.91
2,2	Ac
2	bDGlcpN	102.1/4.76	55.9/3.79	79.5/3.74	72.5/3.67	77.1/3.44	62.1/3.75
	x?Gro-al	104.1/5.13	80.4/3.96	61.5/3.7-3.8

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

CC(=O)N[C@H]1[C@H](OC(C=O)CO)O[C@H](CO)[C@@H](O)[C@@H]1O[C@H]1O[C@H](CO)[C@H](O)[C@H](O)[C@H]1NC(C)=O

496.466 g/mol (C₁₉H₃₂N₂O₁₃)